Earth-moving machines are used to move and relocate various materials and other objects about a worksite. An example of an earth-moving machine may be a loader, which may be propelled on wheels or continuous tracks, having a lift arm and bucket for lifting, transporting, and dumping material. Other possible examples of earth-moving machines may include bulldozers, dump trucks, and the like. To power the earth-moving machine, the machine may include a prime mover such as an internal combustion engine, e.g., a diesel compression ignition engine, which combusts hydrocarbon-based fuels to convert the potential chemical energy therein into a mechanical or motive force. The generated power can be utilized by a number of components on the earth-moving machine including drive components to propel the machine, steering assemblies for direction control, and work implements connected to the machine.
To distribute the generated power, the prime mover may be associated with a hydraulic system that distributes pressurized hydraulic fluid about the earth-moving machine to actuate the various components. A typical hydraulic system may include a common reservoir for containing low pressure hydraulic fluid, one or more pumps operatively coupled to the prime mover to pressurize the fluid, and a plurality of hydraulic actuators disposed about the earth-moving machine that convert fluid pressure into physical force and motion. High pressure hydraulic hoses or pipes can be included to direct the hydraulic fluid about the machine and between the hydraulic components. The components and hoses may be arranged in one or more hydraulic circuits organized to direct hydraulic fluid from the reservoir through the components and back to the reservoir for reuse.
Because the hydraulic system may include a single prime mover and possibly a common reservoir, the system needs to be designed to allocate the utilities of these common resources to meet the requirement of the different components and subassemblies on the earth-moving machine. Further, the power requirements of the earth-moving machine may change as the machine performs different operations at different times. U.S. Pat. No. 8,336,232 (“the '232 patent”), assigned to the assignee of the current application, describes an arrangement or architecture for a hydraulic system to selectively allocate the pressurized hydraulic fluid between different applications on the earth-moving. In particular, the '232 patent describes a wheel loader having a lift circuit operatively associated with the lift arm and a tilt circuit operatively associated with the bucket. A combiner valve is disposed between and in fluid communication with the lift circuit and the tilt circuit to selectively redirect hydraulic fluid between the circuits based on the requirements and capacities of the hydraulic system. The present disclosure is directed to addressing similar considerations to those described in the '232 patent.